<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <script>
        function abc(){
            var oldstr = document.getElementById('old');
            var newstr = document.getElementById('new')
            var reg = /^\s*|\s$/g


            newstr.value = oldstr.value.replace(reg,'');

        }
    </script>


</head>
<body>
    过滤前:<input type="text" id="old"><button onclick="abc()">过滤<tton><br>

    过滤后:<input type="text" id="new">
</body>
</html>